At the present time, there is a significant amount of glass used for the exterior glazing of buildings. Not only is this glass designed to allow people within the building to look out of the same, but it is also intended to give the building a very asthetic and pleasing look. The richness of color of a building when viewed from its exterior is a very important item to an architect specifying the type of glass to be used in forming the building. If a particular color of glass has very desirable asthetic qualities, it can become very popular for architects in designing new buildings. Therefore, the development of a coated glass sheet that has asthetically pleasing qualities is a significant commercial event. The designation by many architects of a particular color of glass can lead to a realization of a significant commercial business in that color of glass by the manufacturer thereof.
This specification is directed to a coated glass sheet as a new article of manufacture. The coated glass sheet is one in which a multilayer coating film is laid down on the glass sheet in order to give a color to it. The color developed in this glass is extremely pleasing and one which is in great demand by architectual designers for use in buildings designed by them.
Prior to preparation of this specification, a search on this subject matter was conducted in the U.S. Patent and Trademark Office. As a result of that search, the following U.S. patents were cited: U.S. Pat. Nos. 3,010,850; 3,264,074; 3,854,892; 4,022,947; 4,101,200; 4,272,588; 4,235,048; 4,382,977; and 4,451,525.
We have reviewed all of the cited patents and are of the opinion that none of them have any significant teachings or suggestions with respect to the subject matter disclosed and claimed in this specification. However, each of the patents will be reviewed briefly below.
U.S. Pat. No. 3,010,850, issued on Nov. 28, 1961 for "Electrically Conducting Coated Glass or Ceramic Article Suitable for Use As a Lens, a Window or a Windshield, or the Like." This patent is directed to an electrically conductive, transparent article which includes a body of glass and a continous, transparent, electrically conductive layer carried by the body. The layer is deposited by molecular deposition and is composed essentially of an intimate molecular mixture of metal and a metallic inorganic dielectric compound. The proportion of the metal to the dielectric compound in the layer and the thickness of the layer on the body of glass is such that the layer is electrically conductive and serves to carry a major portion of electric current carried by the body.
U.S. Pat. No. 3,264,074, issued on Aug. 2, 1966, for "Thin Film Electron Emissive Electrode." This patent is directed to a thin film, electron-emissive electrode with good adherence characteristics on an insulating base. This unit comprises a glass substrate, a first thin film of a berylium-copper alloy deposited on the substrate, and a second thin film of an electron-emissive iron and nickel composition deposited on the first layer.
U.S. Pat. No. 3,854,892, issued on Dec. 17, 1974, for "Direct Bonding of Metals with Metal-Gas Eutectic." This patent describes a method for direct bonding of metallic members to other metallic members with a metal-gas eutectic. The method comprises placing a metal member such as copper, for example, in contact with another metal member, such as nickel, for example, and heating the metal members to a temperature slightly below the melting point of the lower melting point metal, for example, approximately 1072.degree. C. for copper. The heating is performed in a reactive atmosphere such as an oxidizing atmosphere, for a sufficient time to create a metal-gas eutectic melt which upon cooling bonds the metal members together.
U.S. Pat. No. 4,022,947, issued on May 10, 1977, for "Transparent Panel Having High Reflectivity for Solar Radiation and Method of Preparing Same." This patent discloses a transparent panel capable of transmitting a desired proportion of visible radiation while reflecting a large proportion of incident solar radiation and a method of preparing the same. The method is carried out by sputtering an iron, nickel and chromium alloy to obtain a transparent metal film and reactively sputtering the same or a similar alloy in the presence of oxygen. In a preferred embodiment, the metal film lies between the substrate and the metal oxide film which provides a continuous protective overlayer.
U.S. Pat. No. 4,101,200, issued on July 18, 1978, for "Coating Composition for a Light Transmitting Absorbing Coating on Substrates." This patent discloses a light transmitting, absorbing coating produced on a substrate by depositing layers of silicon in an oxidizing residual gas atmosphere and chrome in a nonoxidizing residual gas atmosphere in alternate layers by cathodic sputtering. The light transmitting layer comprises a substrate having a coating of a bluish-gray transmission color which comprises a plurality of alternate chrome and silicon dioxide layers with the thickness of individual chrome layers being smaller than 10 nm.
U.S. Pat. No. 4,272,588, issued on June 9, 1981, for "Oxide Protected Mirror." This patent discloses a mirror made by applying a coating to a highly reflective surface of a substrate. The coating is prepared from a composition of an alkoxide having the general formula M[OR].sub.n where M is 0-100% titanium, 0-25% silicon, 0-100% tantalum, or 0-15% of a metal ion which forms an alkoxide, R is alkyl from C.sub.1 to C.sub.6 and n is the valence of M, about 1.7 to about 8 mols of water per mol of alkoxide, sufficient alcohol to give solids content of 0.5 to about 15%, and a sufficient amount of a suitable acid to prevent cloudiness. The coated substrate is fired at about 200.degree.-600.degree. C. to form an oxide coating which is substantially oxygen-impervious. Additional layers of the coating may be applied and fired until the oxide coating is about 200-500 angstroms thick, avoiding quarter-wave thickness.
U.S. Pat. No. 4,235,048, issued on Nov. 25, 1980, for "Reversible Window Unit for Alternately Reflecting and Absorbing Solar Energy." This patent discloses a multiple layer coating on a window unit so that the unit can function efficiently as a solar energy collector in winter and as a heat shield in summer. The coating comprises a layer of metal which provides high reflectance of incident solar energy from one side of a coated transparent substrate and a layer which provides high absorption of incident solar energy by the other side of the coated substrate.
U.S. Pat. No. 4,382,977, issued on May 10, 1983, for "Method of Producing Smooth Metallic Layers on a Substrate." This patent discloses a method in which smooth layers of metal are produced on a glass substrate where a large differential expansion coefficient of the metal relative to the substrate produces very large stresses in the metal when the metal substrate is subjected to a post-deposition anneal. The method of the patent involves depositing a layer of metal having a very small self diffusion coefficient at the anneal temperature prior to deposition of the metal having the large differential expansion coefficient.
U.S. Pat. No. 4,451,525, issued on May 29, 1984, for "Products Having Compound Membrane." This patent discloses a product with a compound membrane which comprises a molded substrate, a metal membrane having an average thickness equal to or less than the maximum surface roughness of the molded substrate on the molded substrate, and a dielectric membrane having a thickness of 100 angstroms or more on the metal membrane.
Upon a reading of the various patents briefly discussed above and a reading of the remainder of this specification, it will become readily apparent to those skilled in the art that the prior art cited in the search did not suggest the subject matter specifically set forth and claimed in this specification.